The most common method of delivering a therapeutic substance, such as a drug or other medication, to the human body is by ingestion. However this method is not suitable for therapeutic substances which may be inactivated by digestive enzymes or by passage through the liver. Ingestion is also less effective for delivering a therapeutic substance in a controlled manner over an extended period of time. Therefore, other routes of administration are used such as a vaginal pessary or rectal suppository. Alternatively, methods of delivering a therapeutic substance in a controlled manner have been developed, including surgical and non-surgical implants.
One of the problems with the vaginal and rectal routes is that the medication often drops out after administration. Also, current implant technology either cannot be removed if it is dissolvable in the skin or elsewhere, or needs to be removed surgically if it is contained within a non-dissolvable structure and then reinserted surgically.
Other examples of known prior art methods of administrating medication are the various intrauterine systems (IUS) and devices (IUD), utilised for the controlled release of a hormone or contraceptive substance. However with this type of system the device needs to be removed and replaced completely if the dose of medication runs out, which is not only inconvenient, but can also be difficult and may be associated with infection. Also, these routes work poorly when it comes to sustained systemic absorption due to their location high in the uterine cavity where the medication tends to linger locally rather than be absorbed into the rest of the body.
The present invention was developed with a view to providing a cervical transfer catheter and method for the controlled release of a therapeutic substance which is less susceptible to the above-noted disadvantages of the prior art. Although the device and method will be described with particular reference to human use, it will be understood that the device and method may also be used with animals.
References to prior art in this specification are provided for illustrative purposes only and are not to be taken as an admission that such prior art is part of the common general knowledge in Australia or elsewhere.